Bit-brace extension.



H. E. PARKER.

BIT BRACE EXTENSION.

APPLICATION rILED-IAII.II.'19I1.

Patented Sept. 25, 1917.

HARRY E. PARKER, 0F NEW BRITAIN, CONNECTICUT, ASSIGNOR TO TI-IE STANLEY RULE & LEVEL COMPANY, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

BIT-BRACE EXTENSION.

Specification of Letters Patent.

Patented Sept. 25, 1917.

To all whom t may concern:

Be it known that I, HARRY E. PARKER, a citizen of the United States of America, residing at New Britain, Hartford county, State of Connecticut, have invented a new and useful vBit-Brace Extension, of which the following is a specification.

The present invention is an extension device for bits, angers and other boring tools and the general objects of the invention are to provide a simple inexpensive and substantially constructed device of this character in which the boring tool may be readily and firmly secured and which will be of a size to follow the boring tool into the cut being made.

Other objects are to provide a simpleconstruction of jaw parts in which the opposite jaws may be made as duplicates instead of right and left-hand jaws as heretofore, to enable an easy assembling or disassembling of the jaws and to prevent the jaws being accidently loosened or opened in the course of boring operations.

In the accomplishment of these objects I employ a tool shank having a suitable driving for engagement in the chuck of a brace or other boring device and 'provide this shank with seats in opposite sides of the end portion thereof to receive duplicate jaw parts, said seats comprising preferably longitudinal inwardly extending grooves or channels receiving shank portions on the jaws and having enlargements receiving enlarged head portions on the ends of the jaws, these head portions on the jaws having a pivoting action in their seats and being detachably held in place therein by springs mounted on the tool shank.y rIhe jaws are closed by a jaw closing member sleeved on the tool shank and having preferably alefthanded screw threaded engagement therewith so as to exert a tightening effect upon the jaws when the same engages with the walls of the bore in which the tool is working.

Other features and details of construction will appear as the specification proceeds, attention being directed to the accompanying drawing wherein I illustrate the invention embodied in a practical and preferred form.

In said drawing:

Figure 1, is a view of the tool in side elevation, the intermediate portion of the shank being broken away, the driving head in the upper end of the shank being shown engaged ina tool chuck and the jaws of the bit extension being shown holding an auger as in the normal use of the device.

Fig. 2, is an enlarged detail view of the lower jaw or chuck end of the tool, with the jaw closing mechanism shown in section.

Fig. 3, is a sectional view of the tool shank and chuck taken on a plane at right angles to the plane of Fig. 2.

Fig. 4, is a cross-sectional view taken substantially on the plane of the line 4 4 of Fig. 1.

Fig. 5, is a view illustrating one of the duplicate chuck jaws in front and edge relations.

The shank or body of the tool is designated 7, the same being of any desired length and being usually provided at one end with a driving head such as that indicated at 8, adapted to be held in a chuck such as indicated at 9 of a brace or other boring device.

l At the opposite or chuck end the shank 7 is formed with seats for holding the chuck jaws, said seats comprising in the illustra- The jaws are provided at their ends withenlargements or heads 14 of a size to tit easily within the enlarged seats 11 provided therefor in the sides of the tool shank and with reduced shank portions 15 guided within the longitudinal grooves or channels 10 provided in the opposite sides of the shank. In the illustration the heads 14 are substantially circular, the seats 11 therefor being of corresponding shape and the inner faces of the heads may be beveled or rounded off as indicated at 16 so as to have a rocking or pivotal engagement in the seats.

heads'near theends thereof, ysuoli springs ,j

thereby having the Veffect vas indicated in Fig.

3 of rocking the jaws on the rounded ,ory

beveled bearing surfaces described so as to swingthenouter ends of the jaws apart or into separated relation.

The springs are shown secured to the tool i shankbymounting themin grooves or channels y19 whichv are in effect narrow continuationsor extensions ofthe grooves in lwhich the jaws are seated, the springs being shown heldy therein by integral lugs orextensions 20 indented from the side Ywalls, of the grooves over the tops of the springs. The head-portions of the jaws are further shown provided with grooves 2l forming vbearing seats for' those portions of the springs engaged therewith.

The` jaws arey closed upon the tool by means comprising, in the present instance, av

jaw closing sleeve 22 slidably engaged over the tool 'shank and forced into closing engagement with the jaws by a screw threaded sleevel28,`lalso engaged on thetool shank, al thrust 'receiving washer 24 being preferably,l

interposed between the adjoining ends of these'two sleeve members.

The'fscrew threaded engagement between' the operatingsl'eeve 28which is in effect, an

operating'4 nut and thefshank of the tool clearly illustrated in Fig. 2, thelsame com-vl prisin'ga left-handed 'screw threaded poi-,

tion 25 on the shank with which the similarly left-handed screw threaded portion` of thebperatingsleeve engages. With this,

construction it is necessary to turny the jaw closing sleeve left handedly to close the jaws, the result` of which is ythat any friction by engagement of said sleeve with the walls of y. the bore in `which the tool is operatiingfhas, a tendency'to further close the jaws rather than loosen them. This is exceedingly valu-.

' able in' working in deep cuts.

The driving head 8 of the tool which s usually 'of squared shape is preferably made large enough to constitute a stop or abutment preventing thesleeves from sliding off Athe tool shank when the sleeve 23 has been turned far enough to disengage it from the screw,

This prevents the threaded :portion 25. y partsfrom becoming lost.` To enable the separation vof the parts when such is desired I have'shown the corners of the driving head screw threaded as indicated at 2'( in ycorrespondence with the left-handed screw threads 25 so that the sleeve 23 may bere-v moved by rotating it over thisscrew threaded abutment head. The jaw engaging sleeve 22 is of sufficiently large internal diameter to slide over the threadedportions of the;

shank s0 that the parts will all slip off the end of theshank when thethreadedisleeve has been disengaged therefrom as described. In constructing the device the lower end Lof the `toolshankfmay .be madel all of one diameter and slightly larger-.than the upper portion of the shank, the left-handed screw Vthreads beingcut in the-upper end of this enlarged portion, the screw threaded sleeve l having its upper threaded end of 'reduced 75 diametento lit this vthreaded po-rtionand its lower portion of the same diameter as the jaw engaging sleeve thnust .ring sov`` 4. x pas to,freelywork.over the non-.threaded por-.-; tion vof thefenlarged part yof ,the shank. f

l Thejadvantages4 of v,theinvention will be apparentjfrom theforegoing, it. being seen.. v that,the, tool isveryr,simple-vandfpractical and that it is easilyhandled and adapted for any place where an extension-of the b-,Orf-Q j ling tool is `rneeded. The making of the jaws 1 as duplicateparts is of ,greatl utility -in cheapenmg the yconstruction of the tool and..

facilitating lthe assemblage ofthe same. The

. the relatively small compact construction. of; f

bit into the out being made.-` What vI-clallfl is: i l. A tool chuck comprising a shank hav- .ing longitudinal grooves,ineoppositewsides '11.. thereofl and Aextending,g-inwardly, from fthe;V end of the shank, ysaid-,.grooves'being laterally enlarged at points inward, from the endn10 5 l of. thefshank to. formenlargedfseats at thef lllelends.ofthegrooves, jaws havingshank-1 f l portions guided in; the ,longitudinal -slots-4 si. and laterallyenlarged heads engagediin the ;l

the tool which enables the. tool to follow the ,the jaws against longitudinal withdrawal ,frompthe grooves and said headshaving a lplvotl-ngwaction inthe seats, provided theref for to enable opening and closing movement of the jaws, springs bearing on .the jaw headsto hold them engaged in the seatsproivided therefor andjaw closing means engagingV over the jaws.`

2' A# 901 Chuck Comprising- L' Stat ling a threaded lportion disposed at a point 12o'- v*inward ,from the endvthereofandgrooves 'L 1n opposite sides thereof with=laterallyenf ,larged seats at the inner ends of said grooves,

jaws mounted atthe end ofthe shank en-w: f

gaged` in said grooves having heads at the i ends thereof prvotally engaged in the'fenlargedy Seats aforesaid, a: jaw yclosing sleeve 'l yslidably engaged over-the atool .shank lat a i point between the jaws thereon and rthe 1 threaded portion, and an internally thread-f fha. f.

seats aforesaid, i said f headsA thereby holding 11:@-

ed operating sleeve engaged over the threaded portion of the tool shank and arranged to force the slidable jaw closing sleeve longitudinally over the jaws.

3. A tool chuck comprising a shank having a threaded portion disposed at a point inward from the end thereof and grooves in opposite sides thereof with laterally enlarged seats at the inner ends of said grooves, jaws mounted at the end of the shank engaged in said grooves having heads at the ends thereof plvotally engaged in the enlarged seats aforesaid, a jaw closing sleeve slidably engaged over the tool shank at a point between the jaws thereon and the threaded portion, an internally threaded operating sleeve engaged over the threaded portion of the tool shank and arranged to force the slidable jaw closing sleeve longitudinally over the jaws and a loose thrust ring interposed between the adjoining ends of the jaw closing sleeve and the threaded operating sleeve.

4. A tool chuck comprising a shank having longitudinal channels in opposite sides thereof extending inward from the end of the shank and provided with enlarged portions disposed inward from the end of the shank and reduced portions extending inward from said enlarged portions, jaws having shank portions guided in the outer portions of the channels and laterally enlarged heads on the ends of said shank portions having rounded under surfaces bearing in the enlarged portions of the channels, springs secured in the reduced portions of the channels at the inner ends of the enlargements therein and bearing on the enlarged head portions at the ends of the jaws, said head portions having grooves in the outer faces thereof receiving` the springs aforesaid and said springs projecting inwardly into engagement with the end portions of the jaws to thereby rock the curved heads of the jaws in their seats and separate the outer ends of the jaws and aw closing means for said jaws.

HARRY E. PARKER.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

